Dante called it “the cursed and unlucky ditch.” Half a millennium later, Tuscany’s Arno river would more than live up to that title. Just before dawn on November 4, 1966, the rain-swollen river abruptly broke its banks; its waters surged through Florence at speeds of 45 miles per hour and flooded the city with 18 billion gallons of mud and grime. Yet for all the destruction the natural disaster unleashed, it would also provide a major turning point for one of the city’s most beloved art-supply shops.

Among Tuscany’s more superstitious residents, l’alluvione (“the flood”) had been a long time coming. Since the Arno’s first recorded flood in 1177, Florence had already been swamped 55 times, with roughly one superflood for each century of its history. As historians would later note, both the earliest and most recent encounters with these superfloods—recorded in 1333 and 1844, respectively—had also arrived on November 4th.

Beyond destroying much of the city’s infrastructure, the flood also desecrated huge swathes of Florence’s cultural patrimony—including priceless works of art. As the New York Times reported, “Some 1,500 pieces [were] disfigured or destroyed, including 320 panel paintings, 629 canvas paintings, 495 sculptures and 124 frescoes.”

Image courtesy of Massimo Zecchi.

Amidst the chaos, an ad hoc group of volunteers lept into action to salvage whatever precious artifacts could be plucked from the soupy detritus that now choked the city. They were known as Angeli del Fango, or “Angels of the Mud.” Massimo Zecchi, co-owner of the iconic Florence art-supply shop that now bears his family’s name, was among them.

“I was 14 years old and remember those moments well,” Massimo recently recalled. “We barely avoided disaster—the waters stopped just a few centimeters short of the powdered pigments on our shelves. The flood dyed the Duomo with a thousand colors.”

A number of high-profile artworks were damaged at the Duomo, the Uffizi, and other churches and institutions, including masterpieces by such

. Giotto’s Campanile, the iconic Duomo bell tower that straddles the domains of art and architecture, was among the most prominent masterpieces harmed.

Soon, Massimo noted, the flood would catalyze a renaissance in the field of artistic restoration. “Entire restoration laboratories were set up to do this work scientifically for the first time,” Massimo said, “which generated demand for new tools and machinery…but also traditional materials that were produced here, as well.”

Image courtesy of Massimo Zecchi.

Massimo was particularly well-positioned to contribute to this new boom given his shop’s stock of historic pigments that restorers needed. His family’s famed art-supply store, officially christened “Zecchi” in 1956, was, even by 1966, widely considered to be Florence’s oldest and most traditional, with earlier iterations of the business dating as far back as the early 1800s. This history—and the shop’s dedication to developing products with the same materials and processes as the earliest Renaissance craftsmen—still sets it apart today.

“In the 1970s, an enthusiasm for ‘modernism’ began to orient artists towards new products and techniques, but we made a different choice,” Massimo explained. “Instead, we have always tried to preserve the sale, use, and knowledge of the ancient painting and craft techniques. Over time, it has become clear that these traditions are not only still valid, but actually more resilient in the long run.”

To these ends, Massimo points to Cennino Cennini’s 14th-century publication Il Libro dell’Arte—widely translated as “The Craftsman’s Handbook,” and the oldest extant Italian text about the practice of painting —as the philosophical foundation for his business. “We want to pass on only the most time-honored techniques,” Massimo added, “and Cennino Cennini has left us the oldest painting manual available.”

When it comes to applying these principles to artistic restoration efforts, nowhere is Zecchi’s iconic approach more valued than in the conversion of lapis lazuli into Blu Oltremare pigment. Mined predominantly from the mountains of Afghanistan, the stone’s lasting and vibrant blue hue has long made it among the most highly coveted raw materials for professional painters. Its name is a testament to the great lengths artists have historically been willing to go to in order to procure it.

Image courtesy of Massimo Zecchi.

“From Afghanistan, ancient shipments of lapis lazuli were transported across the Silk Road, into Palestine, and finally across the Mediterranean to Italy,” Massimo explained. “For this journey it was called ‘Blu Oltremare,’ which translates to ‘Overseas Blue.’”

Then, as now, artists were unanimous in their praise for the pigment’s rare brilliance, which was used widely in the most ambitious works of Renaissance art. In the words of one Theodore Turquet de Mayerne, a Genevan-born physician who collected pigment recipes, “[lapis lazuli] is the diamound of all colours by reason of his never fading perfectione.” Two centuries prior, Cennini had been even more effusive. “Blu Oltremare is a colour noble, beautiful, and perfect beyond all other colours,” he wrote, “and there is nothing that could be said of it but it will still exceed this praise.”

Six centuries on, few still maintain this level of reverence for the pigment quite like the Zecchi family, who continue to produce Blu Oltremare through the same laborious, multi-day process employed by their Renaissance predecessors. Their scrupulous attention to detail has not gone unnoticed.

When disaster befell yet another Giotto masterpiece following a 5.7 magnitude earthquake in 1997—this time the artist’s frescoes in the Basilica of Saint Francis of Assisi—conservators turned to Zecchi to supply the vaunted pigment. Massimo was hardly surprised. “No color has a depth and intensity like this,” Massimo said. “And nobody in the world has a Blu Oltremare as deep as we do.”

Ian Shank

Correction: A previous version of this article misstated that Zecchi provided Blu Oltremare pigment for the restoration of Michelangelo’s Doni Tondo. Zecchi did provide the pigment for the restoration of Giotto’s frescoes in Assisi.